EQ a room with a RTA and Noise Oscillator

The Behringer X32 and XAir have an oscilator and RTA (Real Time Analyser) inbuilt. Failing that - you can use the Android App Audio Tools to generate and show the RTA spectrum. You will need a calibrated mic.

Setup a pink noise oscilator. Run at around 80dB. Use hearing protection.

Setup a calibrated (RTA) microphone.

Set the RTA meter on flat, Z or C weighted. Do not use A weighted (which is weighted for human hearing sensitivity).

Insert a GEQ for the FOH.

Lift up frequencies that are lacking to get a straight level. Some techs like higher lows, with a roll off on the high.

Ignore the rolloff lower than 40Hz - the speakers cannot physically handle this efficently and we cannot hear it. Trying to boost these frequencies is a waste of power.

Notes:

The room acoustics will change when people arrive - so don't go too crazy.

Cut the Oscilator and watch the decay. The EQ might need tweeking to dampen the echo'ing freq.

Other Ref:

Check out Drew's video on using the X32 Pink Noise and the Built-In RTA to Ring Out Your Room. For the RTA he uses (see 4:00):

GEQ Defaults Checkbox: Use RTA Source (checked)

RTA Source Checkbox: Solo Priority (checked)

Select: SPrio - Solo Priority. So when we solo a channel, the screen shows that is being solo'ed.